Point Blue staff and interns collect weather data several times each day at the Palomarin Field Station to understand how climate change (over the long-term) and weather fluctuations (over the short-term) affect birds. Weather plays a huge role in the daily lives of birds, from successfully raising young to surviving the winter, while climate change can affect the long-term stability of bird populations.

How has the climate changed?

To examine long-term weather patterns, we calculated annual average temperatures and total rainfall at Palomarin since 1975. Both measures have fluctuated over the last 40+ years, but temperatures have recently become much warmer. Through 2018, the most recent year of data included here, the hottest year we’ve recorded was in 2017. The wettest year we’ve recorded was in 1997-98 (during a strong El Niño). Recent years have been relatively dry, punctuated by a few wet winters.

Average temperatures and rainfall recorded at the Palomarin Field Station each year, 1975–2018. Average temperatures are calculated from the average of the daily high and low temperatures. Rainfall totals are calculated from July through June of the following calendar year, to capture an entire winter rainy season.

Why is tracking weather and climate important for bird conservation?

Understanding how birds are affected by weather and climate requires long-term monitoring over decades. Because of our long-term bird monitoring and weather data collection at Palomarin, Point Blue has been able to identify changes in both the bird populations and the local climate, and uncover the links between them. This information helps us understand how well birds are adapting to climate change, and which species may be more vulnerable to climate change and may require more conservation attention. Here are just a couple examples of how our research has identified how birds are responding to global climate change.

Migration Timing

A changing climate may influence the seasonal timing (“phenology”) of blooming plants, hatching insects, and bird migration or nesting. In some cases, birds may not be able to easily change the timing of their migration to keep up with changes in the timing of their plant and insect food supplies, while others are shifting to try to stay in sync.

We have examined the dates migratory species arrive at Palomarin in the spring, and found that some species are arriving earlier (Orange-crowned Warbler), some are arriving later (Wilson’s Warbler), while others haven’t changed at all (Swainson’s Thrush).


Photo by Hannah Conley / Point Blue


Photo by Ian Tait / Point Blue


Photo by Rich Stallcup



For species that arrive at Palomarin in the fall, some species are arriving earlier (Golden-crowned Sparrow and Ruby-crowned Kinglet), while others haven’t changed at all (Fox Sparrow and Hermit Thrush).


Photo by Hannah Conley / Point Blue


Photo by Ryan DiGaudio


Photo by Miguel Demeulemeester / Point Blue


Photo by Point Blue

We don’t yet know exactly why some species are changing their migration timing while others are not, and whether shifts in migration timing are helping species adapt to changes in the timing of their food supply or other necessary resources. Future research could examine whether individuals that arrive earlier or later are more successful in raising young or surviving the winter, whether the optimal arrival time has changed over the years, and whether it depends on how far the birds are migrating.

Body Size

Birds at Palomarin have been getting longer wings! A 2012 study led by graduate student Rae Goodman uncovered this surprising finding using banding data from Palomarin and the San Francisco Bay Bird Observatory. Studies from other parts of the world have found that birds are getting smaller, thought to be related to increasing temperatures. Longer wings could indicate birds in California are getting larger, possibly in response to increasing variability in our climate or more favorable conditions than in other places.

To understand why birds have been getting longer wings, future research could examing whether birds with longer wings arrive at to the Palomarin Field Station at different times than birds with shorter wings, or whether they are better at raising young or surviving the winter.

Measuring the wing chord (length) of a Red-breasted Sapsucker. Wing chord was one of the measurements found to be increasing over time. Photo by Mark Dettling / Point Blue

How did we collect these data?

Solar-powered weather station at Palomarin. Photo by Hilary Allen / Point Blue

The tools have changed over time, but we have been collecting weather data on site since 1968, including daily records of precipitation, fog, temperature, cloud cover, wind, and barometric pressure. The bird body size and arrival dates data come from our long-term mist netting and banding operation. All of these data are collected by staff, volunteers, and especially the hundreds of interns who have trained at Palomarin over the years.

Plan your visit!

Although the Palomarin Field Station is currently closed to the public, we welcome you to plan your visit in the near future. You can see our weather station and watch how we collect weather data during a bird banding demonstration. Visitors can drop in and join our intern and staff biologists to learn how we collect this data — and hopefully see a bird in the hand! More information on visiting and scheduling groups.